This is up for debate.
Ultimately, what he’s saying is that liberals failed by putting an emphasis on an acknowledgement and celebration of our differences instead of our similarities. The rest of his piece provides evidence of this assertion.
But when it came to life at home, she tended on the campaign trail to lose that large vision and slip into the rhetoric of diversity, calling out explicitly to African-American, Latino, L.G.B.T. and women voters at every stop. This was a strategic mistake. If you are going to mention groups in America, you had better mention all of them. If you don’t, those left out will notice and feel excluded. Which, as the data show, was exactly what happened with the white working class and those with strong religious convictions. Fully two-thirds of white voters without college degrees voted for Donald Trump, as did over 80 percent of white evangelicals.